阅读说明：本技术 机器人的故障诊断装置及其机器人系统 (Fault diagnosis device for robot and robot system thereof ) 是由 片山周 于 2020-09-18 设计创作，主要内容包括：本发明高精度地检测表示机器人的状态的发光部的故障。故障诊断装置(20)诊断发光部(14)的故障,该发光部(14)通过发光颜色不同的多种LED(15～17)被个别地通电并点亮,从而发出与机器人(2)的动作状态相应的颜色的光。故障诊断装置(20)具备：通电控制部(23),控制对LED(15～17)的通电；电压检测部(24),检测根据LED(15～17)的端子电压而变化的诊断电压(Vd)；以及故障检测部(25),根据基于通电控制部(23)的通电的控制状况与基于电压检测部(24)的诊断电压(Vd)的检测值,检测发光部(14)的故障。(The invention detects the fault of the light emitting part which represents the state of the robot with high precision. A failure diagnosis device (20) diagnoses a failure of a light emitting section (14), and the light emitting section (14) emits light of a color corresponding to the operating state of a robot (2) by being individually energized and illuminated by a plurality of types of LEDs (15-17) having different light emitting colors. A failure diagnosis device (20) is provided with: an energization control unit (23) that controls energization of the LEDs (15-17); a voltage detection unit (24) that detects a diagnostic voltage (Vd) that changes in accordance with the terminal voltage of the LEDs (15-17); and a failure detection unit (25) that detects a failure of the light emitting unit (14) on the basis of the control status based on the energization by the energization control unit (23) and the detection value of the diagnostic voltage (Vd) by the voltage detection unit (24).)

1. A failure diagnosis device for a robot, which diagnoses a failure of a light emitting section that emits light of a color corresponding to an operating state of the robot by being individually energized and turned on by a plurality of types of light emitting diodes having different light emitting colors, and is provided in the robot, the failure diagnosis device for a robot comprising:

an energization control unit that controls energization to the light emitting diode;

a voltage detection unit that detects a diagnostic voltage that varies according to a terminal voltage of the light emitting diode; and

and a failure detection unit that detects a failure of the light emitting unit based on a control state based on the energization of the energization control unit and a detection value of the diagnostic voltage based on the voltage detection unit.

2. The failure diagnosis device of a robot according to claim 1,

the energization control unit performs energization to the other one of the light emitting diodes while the operating state of the robot is a state in which only one of the light emitting diodes of the light emitting unit is energized,

the failure detection unit detects a failure of the light emitting unit based on a detection value of the diagnostic voltage during a period in which the energization control unit energizes the other one of the light emitting diodes.

3. The failure diagnosis device of a robot according to claim 1 or 2,

the energization control unit performs energization to the other plurality of light emitting diodes while the operating state of the robot is a state in which only one of the light emitting diodes of the light emitting unit is energized,

the failure detection unit detects a failure of the light emitting unit based on a detection value of the diagnostic voltage during a period in which the energization control unit energizes the other plurality of light emitting diodes.

4. The failure diagnosis device of a robot according to claim 2 or 3,

the energization control unit controls energization of the other light emitting diodes so that the luminance of the light emitting diode is lower than that in a steady state.

5. The failure diagnosis device of a robot according to any one of claims 1 to 4,

the lighting device further includes a notification unit configured to notify that the light emitting unit has failed, by a method different from lighting of the light emitting diode, when the failure detection unit detects the failure of the light emitting unit.

6. The failure diagnosis device of a robot according to any one of claims 1 to 5,

the energization control unit is configured to control the robot so that safety of a user using the robot is not lost even if energization of the light emitting diode is performed regardless of an operating state of the robot.

7. The failure diagnosis device of a robot according to any one of claims 1 to 5,

even when the energization control unit energizes the light emitting diodes regardless of the operating state of the robot, the plurality of types of light emitting diodes each emit a color that makes it difficult for a user using the robot to erroneously recognize the state of the robot.

8. The failure diagnosis device of a robot according to any one of claims 1 to 7,

the light emitting section includes red, green, and blue light emitting diodes as three light emitting diodes corresponding to three primary colors of light,

when the robot is in a first state in which a predetermined operation is automatically executed, the red light-emitting diode, the green light-emitting diode, and the blue light-emitting diode are energized to emit white light,

when the robot is in a second state in which an error of relatively high importance occurs, the red light emitting diode is energized to emit red light,

when the robot is in a third state in which an error of relatively low importance occurs, the red light emitting diode and the green light emitting diode are energized to emit yellow light,

when the state of the robot is a fourth state in initialization for initialization, the green light emitting diode is energized to emit green light,

and a fourth mode in which the robot is operated manually by a user who uses the robot, and the robot is in a fourth state, wherein the blue light-emitting diode is energized to emit blue light.

9. A robot system includes:

an industrial robot;

a light emitting unit that is provided in the robot and emits light of a color corresponding to an operating state of the robot by being individually energized and turned on by a plurality of types of light emitting diodes having different emission colors;

an energization control unit that controls energization to the light emitting diode;

a voltage detection unit that detects a diagnostic voltage that varies according to a terminal voltage of the light emitting diode; and

and a failure detection unit that detects a failure of the light emitting unit based on a control state based on the energization of the energization control unit and a detection value of the diagnostic voltage based on the voltage detection unit.

Technical Field

The present invention relates to a robot failure diagnosis device and a robot system, and more particularly, to a robot failure diagnosis device and a robot system suitable for an industrial robot and used for diagnosing a failure of a light emitting unit that emits light of a color corresponding to an operating state of the robot.

Background

Conventionally, as disclosed in patent document 1, for example, there is a robot including a light emitting unit that emits light of a color corresponding to an operating state or the like. With this configuration, the operator can grasp the operation state of the robot and the like based on the color of the light emitted by the light emitting unit. Such a light-emitting portion includes the following structures: three light emitting diodes corresponding to red, green, and blue, which are three primary colors of light, are provided, and light of a color corresponding to the state of the robot is emitted by individually energizing the light emitting diodes. In this specification, a light-emitting diode is sometimes referred to as an LED.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-43438

Disclosure of Invention

Technical problem to be solved by the invention

In the above configuration, when a failure occurs in each LED constituting the light emitting portion, the configuration for driving the LEDs, or the like, the light emitting portion may emit light of a color different from the color corresponding to the state of the robot, which may result in a reduction in safety of an operator who performs a predetermined operation using the robot. For example, even if the robot state is the automatic mode, when the light emission color of the light emitting section is a color indicating the direct teaching mode, the following problem occurs. The automatic mode is a state in which the robot automatically executes a predetermined operation in accordance with a program prepared in advance, and the direct teaching mode is a state in which a worker can manually operate the robot arm to perform teaching.

That is, if the light emission color of the light emission unit is a color indicating the direct teaching mode, the operator erroneously recognizes that the robot is in the direct teaching mode. Therefore, the worker approaches the robot for teaching and tries to contact the robot arm. However, in this case, since the robot automatically performs a predetermined operation, the robot arm or the like may come into contact with a worker who approaches the robot.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a robot failure diagnosis device capable of detecting a failure of a light emitting portion indicating an operating state of a robot with high accuracy.

Technical solution for solving technical problem

A failure diagnosis device for a robot according to a first aspect is a device for diagnosing a failure of a light emitting unit that emits light of a color corresponding to an operating state of the robot by being individually energized and turned on by a plurality of types of light emitting diodes having different light emitting colors. The failure diagnosis device is provided with: an energization control unit that controls energization to the light emitting diode; a voltage detection unit that detects a diagnostic voltage that varies according to a terminal voltage of the light emitting diode; and a failure detection section.

The terminal voltage of the light emitting diode changes according to the state of energization to the light emitting diode. Therefore, the diagnostic voltage varies depending on the respective states of energization to the plurality of light emitting diodes. That is, in the above configuration, the diagnosis voltage is a voltage value specific to each of the conduction states of the plurality of light emitting diodes. In the above configuration, the current supply state to the plurality of light emitting diodes matches the control state based on the current supply by the current supply control unit in the normal case where no failure occurs in the light emitting diodes and the configuration for driving the light emitting diodes, but does not match the control state based on the current supply by the current supply control unit in the abnormal case where a failure occurs in the light emitting diodes and the configuration for driving the light emitting diodes.

Therefore, in the above configuration, the diagnostic voltage is substantially the same as a voltage value corresponding to the energization state to the plurality of light emitting diodes which can be estimated from the control state of the energization by the energization control unit in the normal state, and the diagnostic voltage is a voltage value different from the voltage value corresponding to the energization state in the abnormal state. In view of these points, the failure detection unit detects a failure of the light emitting unit based on the control state based on the energization by the energization control unit and the detection value of the diagnostic voltage based on the voltage detection unit. With this configuration, it is possible to detect a failure of the light emitting section with high accuracy.

In general, the terminal voltage of the light emitting diode is substantially zero when the light emitting diode is not energized, and is a voltage value corresponding to the forward voltage when the light emitting diode is energized. In addition, forward voltages of the light emitting diodes are voltage values different from each other for each of light emission colors thereof. Therefore, the failure detection unit having the above configuration can also determine which of the plurality of types of light emitting diodes and the configuration for driving the light emitting diodes has failed by taking such a difference in forward voltage into consideration.

In the configuration described in the first aspect, the following method can be adopted: that is, in a state where all the light emitting diodes are not energized (not lit), any light emitting diode is energized (lit) to perform failure diagnosis of the light emitting section. However, in this method, the state in which the light-emitting portion does not emit light is suddenly changed to a state in which the light-emitting portion emits light of a color that is not related to the operating state of the robot. In this case, since the light emitting unit is shifted from the non-light emitting state to the light emitting state, the user (operator) using the robot can easily recognize the change. Therefore, the operator may notice that the light emitting unit suddenly emits light at a timing other than the timing expected by the operator, and may feel uneasy.

Therefore, in the failure diagnosis device for a robot according to the second aspect, the energization control unit energizes only one light emitting diode of the light emitting unit while the operating state of the robot is in a state in which the other light emitting diode is energized. The failure detection unit according to the second aspect detects a failure of the light emitting unit based on the detected value of the diagnostic voltage during the period when the energization control unit energizes another one of the light emitting diodes as described above.

Thus, the light emitting section does not suddenly shift from a non-light emitting state to a light emitting state. In this case, the light emission color of the light emitting section changes only from the light emission color of the one light emitting diode to which power is originally supplied to a mixed color in which the light emission colors of the other light emitting diodes are mixed with the light emission color, and this change is difficult to be recognized by the operator. Therefore, according to the above configuration, the diagnosis of the light emitting section can be performed without giving the operator a sense of unease.

In the failure diagnosis device for a robot according to the third aspect, the energization control unit energizes the plurality of other light emitting diodes while the operating state of the robot is a state in which only one light emitting diode of the light emitting unit is energized. The failure detection unit according to the third aspect detects a failure of the light emitting unit based on the detected value of the diagnostic voltage during the period when the energization control unit energizes the other plurality of light emitting diodes as described above.

Thus, the light emitting section does not suddenly shift from a non-light emitting state to a light emitting state. In this case, the light emission color of the light emitting section changes only from the light emission color of the one light emitting diode to which power is originally supplied to a mixed color in which the light emission colors of the other light emitting diodes are mixed with the light emission color, and such a change is difficult to be recognized by the operator. Therefore, according to the above configuration, the diagnosis of the light emitting section can be performed without giving the operator a sense of unease.

In the failure diagnosis device for a robot according to the fourth aspect, the energization control unit controls energization of the other light emitting diodes so that the luminance of the light emitting diode is lower than that in a steady state. In this way, the degree of color change from the light emission color of the one light emitting diode to which power is supplied to the mixed color can be suppressed to a small level, and such a change is more difficult for the worker to recognize. Therefore, according to the above configuration, the diagnosis of the light emitting section can be performed while the possibility that the operator feels uncomfortable is further suppressed to a low level.

The failure diagnosis device for a robot according to a fifth aspect further includes a notification unit that notifies that a failure has occurred in the light emitting unit by a method different from lighting of the light emitting diode when the failure detection unit detects a failure of the light emitting unit. When a failure of the light emitting unit is detected, there is a high possibility that the lighting of the light emitting diode is not normally performed, and therefore, in the method of notifying the failure of the light emitting unit by lighting the light emitting diode, there is a possibility that reliable notification cannot be realized. According to the above configuration, the occurrence of a failure in the light emitting unit is notified by a method different from the lighting of the light emitting diode, and therefore, reliable notification can be realized.

In the failure diagnosis device for a robot according to the sixth aspect, the energization control unit is configured to control the energization of the light emitting diode so that the safety of a user using the robot is not significantly impaired, regardless of the state of the robot. According to this configuration, even when the energization control unit energizes the light emitting diode in a manner different from the normal one for the failure diagnosis of the light emitting unit, there is no problem in the safety of the user.

In the failure diagnosis device for a robot according to the seventh aspect, when the energization control unit energizes the light emitting diodes regardless of the state of the robot, each of the plurality of light emitting diodes has a color that makes it difficult for a user using the robot to erroneously recognize the state of the robot. In this way, even when the energization control unit energizes the light emitting diode in a manner different from the usual manner for the failure diagnosis of the light emitting unit, the user does not erroneously recognize the state of the robot due to the light emitting color of the light emitting unit, and therefore, the user does not come close to the robot carelessly, and there is no problem in safety.

In the failure diagnosis device for a robot according to the eighth aspect, the light emitting section including the red light emitting diode, the green light emitting diode, and the blue light emitting diode, which are three light emitting diodes corresponding to the three primary colors of light, is set as the object of diagnosis. When the robot is in a first state in which predetermined operations are automatically executed, the red light emitting diode, the green light emitting diode, and the blue light emitting diode are energized, and the light emitting section emits white light. When the robot state is in a second state in which an error of relatively high importance occurs, the red light emitting diode is energized, and the light emitting section emits red light.

When the operating state of the robot is in a third state in which an error of relatively low importance occurs, the red light-emitting diode and the green light-emitting diode are energized, and the light-emitting portion emits yellow light. When the robot state is the fourth state in the initialization for initialization, the green light emitting diode is energized, and the light emitting section emits green light. When the robot is in a fifth state which is a direct teaching mode in which a user using the robot can manually operate the robot to perform teaching, the blue light emitting diode is energized, and the light emitting section emits blue light.

By using such a light-emitting unit as a target of failure diagnosis, the following effects can be obtained. In other words, in this case, the operation states of the robot in which only one light emitting diode is energized are the second state, the fourth state, and the fifth state. According to the above configuration, even if the other one of the light emitting diodes is energized for the purpose of diagnosing a failure in such a state, it is possible to eliminate the fear of the safety of the worker being lowered. The reason for this will be explained below.

First, even if the robot is in the second state, the light emitting color of the light emitting section changes to magenta, which is a mixed color of red and blue, and does not change to a color indicating another state of the robot, even if the robot is energized to the blue light emitting diode, so that the worker does not erroneously recognize the state of the robot and carelessly approaches the robot, and the risk of a reduction in safety can be eliminated. In the second state of the robot, even if the green light emitting diode is energized, the light emitting color of the light emitting section changes to yellow which is a mixed color of red and green. In this case, yellow corresponds to the third state, and is a color indicating that the state of the robot is wrong, as with red, which is the original light emission color. Therefore, even if the worker notices that the emission color changes from red to yellow, the worker does not recognize that the state of the robot is wrong and does not approach the robot carelessly, and thus the risk of a reduction in safety can be avoided.

In the fourth state, even if the red light-emitting diode is energized, the light-emitting color of the light-emitting portion changes to yellow, which is a mixed color of green and red. As described above, yellow is a color indicating that the state of the robot is wrong. Therefore, even if the worker notices that the light emission color changes from green to yellow, the state recognized as the robot changes from initialization to error, and the worker does not come close to the robot carelessly, and the risk of a reduction in safety can be eliminated. In addition, even when the robot is in the fourth state, even if the blue light emitting diode is energized, the light emitting color of the light emitting section changes to cyan which is a mixed color of green and blue, and does not change to a color indicating another state of the robot, so that the worker does not erroneously recognize the state of the robot and carelessly approaches the robot, and the risk of a reduction in safety can be eliminated.

In the fifth state of the robot, even if the red light emitting diode is energized, the light emitting color of the light emitting section changes to magenta which is a mixed color of blue and red, and does not change to a color indicating another state of the robot. In addition, even when the robot is in the fifth state, even if the green light emitting diode is energized, the light emitting color of the light emitting section changes to cyan which is a mixed color of blue and green, and does not change to a color indicating another state of the robot, so that the worker does not erroneously recognize the state of the robot and carelessly approaches the robot, and the risk of a reduction in safety can be eliminated.

Further, according to the above configuration, even when the other two light emitting diodes are energized for the purpose of diagnosing a failure in a state where only one light emitting diode is energized, or when the other one light emitting diode is energized for the purpose of diagnosing a failure in a state (third state) of the robot in which the two light emitting diodes are energized, it is possible to eliminate the fear of the safety of the worker being lowered. In these cases, the light emitting color of the light emitting unit is white, and white is a color indicating a first state in which the robot automatically performs a predetermined operation. Therefore, even if the worker notices that the light emission color changes from the original color to white, the state recognized as the robot changes from the state indicated by the original color to the first state, and the worker does not come close to the robot carelessly, and the risk of the safety degradation can be eliminated.

Drawings

Fig. 1 is a diagram schematically showing the configuration of a robot system according to a first embodiment.

Fig. 2 is a diagram schematically showing an electrical configuration of the robot system of the first embodiment.

Fig. 3 is a diagram schematically showing the processing contents in the first diagnostic method of the first embodiment.

Fig. 4 is a timing chart schematically showing signals of each part when the robot of the first embodiment is in the second state.

Fig. 5 is a diagram schematically showing the processing content in the second diagnostic method of the first embodiment.

Fig. 6 is a diagram schematically showing the processing content in the third diagnostic method of the first embodiment.

Fig. 7 is a diagram schematically showing the contents of the faulty portion specifying process of the first embodiment.

Fig. 8 is a diagram schematically showing the structure of the light-emitting section of the second embodiment.

Description of the reference numerals

2: robot

14. 31: light emitting part

15: red light emitting diode

16: green light-emitting diode

17: blue light emitting diode

20: fault diagnosis device

23: conduction control unit

24: voltage detection unit

25: failure detection unit

26: notification part

Detailed Description

Hereinafter, a plurality of embodiments will be described with reference to the drawings. In addition, substantially the same components in the respective embodiments are denoted by the same reference numerals, and descriptions thereof are omitted.

(first embodiment)

The first embodiment will be described below with reference to fig. 1 to 7.

As shown in fig. 1, a robot system 1 includes a vertical articulated robot 2, and a controller 3 that controls the operation of the robot 2 is provided inside a base 4. Further, in fig. 1, the controller 3 is depicted as a rectangular box shape, but actually takes a shape matching the shape of the base 4. The robot system 1 is used for general industrial purposes. The robot 2 is a so-called six-axis vertical articulated robot.

A shoulder 5 is connected to the base 4 via a first shaft having an axial center in the z direction so as to be rotatable in the horizontal direction. The shoulder 5 has a second shaft having an axis in the y direction, and a lower end portion of a first arm 7 extending upward is connected to the second offset arm 6 extending in the y direction so as to be rotatable in the vertical direction. A third axis having an axis in the y direction is provided at the distal end portion of the first arm 7, and a second arm 9 is connected to the third offset arm 8 extending in the-y direction so as to be rotatable in the vertical direction. The second robot arm 9 includes a base portion 9a and a tip portion 9 b.

The second arm 9 has a fourth axis having an axis in the x direction, and the tip portion 9b is connected to the base portion 9a so as to be rotatable by twisting. A fifth axis having an axis in the y direction is provided at the tip end portion of the second arm 9, and a wrist 11 is connected to the fifth offset arm 10 extending in the-y direction so as to be rotatable in the vertical direction. A flange, not shown, and a robot hand 12 are rotatably connected to the wrist 11 via a sixth axis having an axis in the x direction. Motors, not shown, are provided as drive sources in correspondence with respective axes provided in the robot 2.

The controller 3 is a control device of the robot 2, and controls the robot 2 by executing a computer program in a control unit constituted by a computer including a CPU, a ROM, a RAM, and the like described below. Specifically, the controller 3 includes a driving unit including an inverter circuit and the like, and drives each motor by, for example, feedback control based on the rotational position of the motor detected by an encoder provided corresponding to each motor.

The controller 3 controls the robot 2 by executing a predetermined operation program so that each arm of the robot 2 automatically executes a predetermined operation. Hereinafter, this operation mode is referred to as an automatic mode. The controller 3 corresponds to direct teaching in which the user manually operates the robot 2 to teach the position and orientation of the arm tip of the robot 2. Hereinafter, an operation mode for performing such direct teaching is referred to as a direct teaching mode.

A window 13 formed in an annular shape from a transparent resin material is provided in a cylindrical portion of the base 4 of the robot 2. As shown in fig. 2, the robot 2 is provided with a light emitting unit 14 that emits light of a color according to the operating state of the robot 2. The light emitted from the light emitting unit 14 is emitted to the outside through (transmitted through) the window unit 13. The light emitting unit 14 is energized and lit individually by a plurality of types of light emitting diodes having different emission colors, and emits light of a color corresponding to the operating state of the robot 2.

In the present embodiment, the light emitting unit 14 includes a red light emitting diode 15, a green light emitting diode 16, and a blue light emitting diode 17 as three light emitting diodes corresponding to the three primary colors of light. Hereinafter, the red light emitting diode 15, the green light emitting diode 16, and the blue light emitting diode 17 are also referred to as R-LED15, G-LED16, and B-LED17, respectively, and are also simply referred to as LED15, LED16, and LED 17. In this case, the LEDs 15-17 are arranged at distances close to a distance at which the light emitting section 14 can emit a combined color of three primary colors of combined light.

In this case, the operating states of the robot 2 include a first state, a second state, a third state, a fourth state, and a fifth state. The first state is a state in which the robot 2 automatically executes a predetermined operation determined in advance, that is, a state in the automatic mode described above. The second state is a state in which an error with a relatively high degree of importance has occurred in the robot 2. An error with a relatively high degree of importance indicates an error with a high degree of urgency with which the robot 2 cannot operate, such as an abnormality occurring in the power supply system.

The third state is a state in which an error with a relatively low importance level has occurred in the robot 2. The error with a relatively low importance level indicates an error with a low urgency level that can be recovered without turning off the power supply when the temperature of the robot 2 rises above a predetermined value, when there is a problem in programming, or the like. The fourth state is a state in initialization in which initialization is performed. The initialization is executed when the power is turned on to the robot system 1, and the robot 2 cannot operate in the initialization. The fifth state is a state in which a user (operator) using the robot can manually operate the robot 2 to perform teaching, that is, a state in which the above-described direct teaching mode is set.

The light emitting unit 14 emits light of a predetermined color in accordance with each of the five operating states. That is, when the robot 2 is in the first state, the R-LED15, the G-LED16, and the B-LED17 are energized, and the light emitting unit 14 emits white light. When the robot 2 is in the second state, the R-LED15 is energized, and the light emitting unit 14 emits red light. When the robot 2 is in the third state, the R-LED15 and the G-LED16 are energized, and the light emitting unit 14 emits yellow light. When the robot 2 is in the fourth state, the G-LED16 is energized, and the light emitting unit 14 emits green light. When the robot 2 is in the fifth state, the B-LED17 is energized, and the light emitting unit 14 emits blue light.

The robot system 1 is provided with a structure for controlling the light emission of the light emitting unit 14 and a structure for detecting a failure of the light emitting unit 14. These configurations will be described below with reference to fig. 2. The light emitting unit 14 includes switches SWr, SWg, and SWb and resistors Rr, Rg, and Rb in addition to the LEDs 15 to 17. The switches SWr, SWg, and SWb are constituted by semiconductor switching elements such as MOSFETs, for example, and are controlled to be turned on and off by command signals Sr, Sg, and Sb, which are binary signals supplied from the controller 3 via the cable 18. Specifically, the switches SWr, SWg, and SWb are turned on when the command signals Sr, Sg, and Sb are at a high level, and turned off when they are at a low level, respectively.

The switch SWr has one terminal connected to the power supply line L1 and the other terminal connected to the ground line L2 via the resistor Rr and the R-LED 15. The switch SWg has one terminal connected to the power supply line L1 and the other terminal connected to the ground line L2 via the resistor Rg and the G-LED 16. The switch SWb has one terminal connected to the power supply line L1 and the other terminal connected to the ground line L2 via the resistor Rb and the B-LED 17.

The power supply line L1 and the ground line L2 are connected to the controller 3 via the cable 18, and thereby a power supply voltage Va for driving the LEDs 15 to 17 is supplied from the controller 3 to the light emitting unit 14. In the above structure, by the switch SWr being turned on, the R-LED15 is energized and lit; with switch SWg turned on, G-LED16 is energized and lit; with switch SWb turned on, B-LED17 is energized and lit. The resistors Rr, Rg, and Rb limit the current flowing through the LEDs 15-17 when the LEDs are energized. That is, the resistors Rr, Rg, Rb function as resistors for current limitation.

The controller 3 includes a failure diagnosis device 20 that controls light emission of the light emitting unit 14 and diagnoses a failure of the light emitting unit 14. The failure diagnosis device 20 includes a microcomputer 21 and a resistor 22. In this specification, the microcomputer is also referred to as a microcomputer. The resistor 22 is provided in series between a power supply line L3 to which the power supply voltage Va is applied and a power supply line L1 for supplying the power supply voltage Va to the light emitting unit 14. The voltage at the terminal of the resistor 22 on the power supply line L1 side is applied to the microcomputer 21 as a diagnosis voltage Vd for diagnosing a failure of the light emitting unit 14.

The microcomputer 21 includes functional blocks such as an energization control unit 23, a voltage detection unit 24, a failure detection unit 25, and a notification unit 26. These functional blocks are realized by the CPU21A included in the microcomputer 21 executing a computer program stored in a main memory (functioning as a non-transitory computer-readable storage medium) such as the ROM21B and executing processing corresponding to the computer program, that is, by software. In the microcomputer 21, reference numerals 21C and 21D denote a RAM and an interface (I/O). Note that at least a part of each functional block may be implemented by hardware.

The energization controller 23 controls energization of the LEDs 15 to 17 of the light emitting unit 14 to generate command signals Sr, Sg, Sb. The command signals Sr, Sg, Sb generated by the energization control unit 23 are supplied to the light emitting unit 14 through the cable 18 and also to the failure detection unit 25. The energization control unit 23 can also use the command signals Sr, Sg, Sb as PWM signals, which are pulse width modulation signals. In this way, the energization controller 23 can control the luminance of the LEDs 15 to 17 when emitting light by controlling the duty ratios of the command signals Sr, Sg, Sb.

The voltage detection unit 24 detects the diagnostic voltage Vd and supplies the detected value to the failure detection unit 25. The failure detection unit 25 recognizes the control state of the energization of the LEDs 15 to 17 by the energization control unit 23 based on the command signals Sr, Sg, Sb. The failure detection unit 25 detects a failure of the light emitting unit 14 as follows based on the control status based on the energization by the energization control unit 23 and the detection value of the diagnostic voltage Vd.

That is, the terminal voltages of the LEDs 15-17 vary according to the state of current applied thereto. Therefore, the diagnostic voltage Vd varies according to the state of current supply to each of the LEDs 15-17. That is, in the above configuration, the diagnostic voltage Vd is a voltage value specific to each of the energization states of the plurality of LEDs 15 to 17. Specifically, when all of the LEDs 15-17 are not energized, the diagnostic voltage Vd is approximately the same voltage as the power supply voltage Va.

When only one of the LEDs 15-17 is energized, the diagnostic voltage Vd is a voltage that is lower than the power supply voltage Va by a predetermined voltage value determined by the terminal voltage (forward voltage) of the LED. When only two of the LEDs 15-17 are energized, the diagnostic voltage Vd is a voltage that is lower than the power supply voltage Va by a predetermined voltage value determined by the voltage at each terminal of the two LEDs.

Further, when all the LEDs 15-17 are energized, the diagnostic voltage Vd is a voltage that is lower than the power supply voltage Va by a predetermined voltage value determined by the voltage at each terminal of all the LEDs 15-17, and the like. Thus, the diagnostic voltage Vd varies according to the terminal voltages of the LEDs 15-17. The diagnostic voltage Vd is a voltage lower when only two LEDs are energized than when only one LED is energized, and a voltage lower when all the LEDs are energized than when only two LEDs are energized.

In the above configuration, when there is no failure in the LEDs 15 to 17 and the configurations for driving the LEDs 15 to 17 (wiring or the like in the current-carrying paths to the switches SWr, SWg, SWb, and the LEDs 15 to LED 17), the current-carrying states to the LEDs 15 to 17 match the control state based on the current-carrying of the current-carrying controller 23, but when there is an abnormality in which a failure occurs in at least any one of them, the current-carrying states to the LEDs 15 to 17 do not match the control state based on the current-carrying of the current-carrying controller 23.

Therefore, in the above configuration, the diagnostic voltage Vd is substantially the same voltage value as a voltage value (hereinafter referred to as an expected value) corresponding to the energization state of the plurality of LEDs 15 to 17, which can be estimated from the control state of energization by the energization control unit 23 in the normal state, whereas the diagnostic voltage Vd is a voltage value different from the expected value in the abnormal state. In view of these points, the failure detection unit 25 detects a failure of the light emission unit 14 based on the control state by the energization control unit 23 and the detection value of the diagnostic voltage Vd by the voltage detection unit 24.

The failure modes that can be detected by the failure detection unit 25 are as follows. Hereinafter, the LEDs 15 to 17 are collectively referred to as LEDs, and the switches SWr, SWg, and SWb are collectively referred to as switches.

(a) Open circuit failure of LED

(b) Short circuit failure of LED

(c) Disconnection of wiring between energization paths to LEDs

(b) Open circuit failure of switch

(e) Short-circuit fault of switch

As described above, the failure mode of the light emitting unit 14 includes not only a failure of the LED itself but also a failure of a structure for driving the LED. In each of the above failure modes, (a), (c), and (d) are failure modes in which the conduction path to the LED is open, and therefore, these failure modes are simply referred to as open failure hereinafter.

When an open fault occurs, the detection value of the diagnostic power supply Vd becomes higher than the expected value because the current does not flow to the conduction path corresponding to the switch even though the conduction control unit 23 has performed on-control of the switch. When a short-circuit failure of the LED occurs, the voltage drop does not occur in the LED and the terminal voltage becomes substantially 0V even if the conduction control unit 23 performs on control of the switch, and the detection value of the diagnostic voltage Vd becomes lower than the expected value.

When a short-circuit failure of the switch occurs, the current flows through the current-carrying path corresponding to the switch despite the off control of the switch by the current-carrying control unit 23, and therefore the detection value of the diagnostic voltage Vd becomes lower than the expected value. The failure detection unit 25 can detect a failure of the light emission unit 14 and determine a failure mode based on the relationship between the detection value of the diagnostic voltage Vd and the expected value.

When the failure detection unit 25 detects a failure of the light emitting unit 14, the notification unit 26 performs a notification process for notifying an operator (user) that a failure has occurred in the light emitting unit 14 by a method different from the lighting of the LEDs 15 to 17. Specific examples of such notification include a sound such as an error sound, a command such as a command to send an error command, and an emergency stop by cutting off the power supply to the robot 2.

Next, a method of diagnosing a failure by the failure diagnosing apparatus 20 configured as described above will be described.

【1】 First diagnostic method

The first diagnostic method is a method capable of diagnosing a failure of the light emitting unit 14 regardless of whether the operating state of the robot 2 is the first state or the fifth state. The first diagnostic method is a method for diagnosing a failure of the light emitting unit 14 without changing the control of the energization of the LEDs 15 to 17 of the light emitting unit 14 as compared with the normal state. In this case, the failure diagnosis device 20 (specifically, the CPU21A) repeatedly executes the processing indicated by each step shown in fig. 3 at predetermined intervals.

First, in step S101, the diagnostic voltage Vd is detected. Next, in step S102, an expected value of the diagnostic voltage Vd corresponding to the control state of the current energization by the current energization control unit 23 is obtained. Thereafter, in step S103, it is determined whether or not the detected value of the diagnostic voltage Vd acquired in step S101 matches the expected value of the diagnostic voltage Vd acquired in step S102. In addition, the expected value may have a predetermined width in order to secure a desired diagnostic accuracy or the like while taking various errors into consideration. In this case, in step S103, it is determined whether or not the detection value is within a range of expected values having a predetermined width.

If the detected value matches the expected value, yes is performed in step S103, and the process ends. In this case, as a result of the failure diagnosis by the failure diagnosis device 20, a result that no failure has occurred in the light emitting unit 14 is obtained. On the other hand, if the detected value does not match the expected value, no in step S103, and the process proceeds to step S104. In step S104, a failure mode and a failure location are determined based on the relationship between the detected value and the expected value.

In the above configuration, when the detected value is higher than the expected value, it can be determined that an open failure has occurred. In the above configuration, when the conduction control unit 23 performs the on control of the switch and the detected value is lower than the expected value, it can be determined that the short-circuit failure of the LED has occurred. In the above configuration, when the switch is off-controlled by the energization control unit 23 and the detected value is lower than the expected value, it can be determined that a short-circuit failure of the switch has occurred.

In the above configuration, the location of the failure can be specified in more detail by considering the following. That is, in general, the forward voltages of the LEDs are voltage values different from each other for each of the emission colors thereof. The diagnostic voltage Vd is a voltage value corresponding to the forward voltage of the LED. Therefore, it is possible to determine which LED corresponds to which open failure has occurred or which LED has short-circuited, based on the difference between the detected value and the expected value and the forward voltage of each LED.

After step S104 is executed, the process proceeds to step S105. In step S105, the failure occurrence-time process is executed. The failure occurrence processing is processing performed when the light emitting unit 14 fails. The processing at the time of occurrence of a failure includes notification processing executed by the notification unit 26. That is, in the failure occurrence processing, the user is notified that a failure has occurred in the light emitting unit 14 by a method other than light emission by the light emitting unit 14, such as sound, command transmission, and emergency stop. After step S105 is executed, the present process ends.

【2】 Second diagnostic method

The second diagnostic method is a method capable of diagnosing a failure of the light emitting unit 14 when the operating state of the robot 2 is the second state, the fourth state, or the fifth state. The second diagnostic method is a method of diagnosing a failure of the light emitting unit 14, while slightly changing the control of the energization of the LEDs 15 to 17 of the light emitting unit 14 as compared with the normal state.

Specifically, in this case, the energization control unit 23 energizes only one LED of the light emitting unit 14 for a predetermined diagnosis period while the operating state of the robot 2 is in a state in which the other LED is energized. The diagnosis period is a relatively short time such as several milliseconds to several hundred milliseconds. That is, in this case, as shown in fig. 4, the energization control unit 23 outputs a pulse-like command signal at a high level to the other LED only in the diagnosis period Ta.

Fig. 4 shows signals of each section when the operating state of the robot 2 is the second state. Therefore, in fig. 4, the command signal Sg corresponding to the LED16 and the command signal Sb corresponding to the LED17 are pulse-like signals that are at a high level only during the diagnosis period Ta. In fig. 4, the high level is referred to as "H" and the low level is referred to as "L" for the command signals Sr, Sg, Sb.

In this case, when the other LEDs are energized, the energization control unit 23 controls the energization so that the luminance of the LED is lower than that in the steady state. By controlling the duty ratio of the command signal as a PWM signal as described above, the luminance of the LED can be controlled by the energization controlling unit 23. In this case, the failure detection unit 25 detects a failure of the light emission unit 14 based on the detection value of the diagnostic voltage Vd in the diagnostic period Ta.

In this case, the failure diagnosis apparatus 20(CPU21A) repeatedly executes the processing shown in fig. 5 at predetermined intervals. First, in step S201, it is determined whether or not the LED15 to the LED17 are in a state of being energized (the second state, the fourth state, or the fifth state). Here, when two or more of the LEDs 15 through 17 are in a state of being energized (the first state or the third state), no in step S201, and the present process ends. That is, in the second diagnostic method, when the robot 2 is in the first state or the third state, the failure diagnosis of the light emitting unit 14 is not performed.

On the other hand, if the current is supplied to only one of the LEDs 15 to 17 (the second state, the fourth state, or the fifth state), yes is performed in step S201, and the process proceeds to step S202. In the following description, each process will be described by taking as an example a case where only the LED15 is energized (second state), but the same process is also performed in a state where only the LED16 or the LED17 is energized (fourth state or fifth state).

In step S202, the diagnostic voltage Vd is detected, and the detected value is acquired as the first detected value Vd 1. Next, in step S203, energization to one LED17 of the two LEDs 16, 17 that are not energized is performed. The period during which the LED17 is energized in step S203 is the diagnosis period Ta described above. In step S204, a diagnostic voltage Vd in a diagnostic period Ta during which the LED17 is energized is detected, and the detected value is acquired as a second detected value Vd 2.

When the open failure corresponding to the LED17 does not occur, the diagnostic voltage Vd in the diagnostic period Ta is lower than the diagnostic voltage Vd in the other periods, as shown by the solid line in fig. 4. On the other hand, when an open failure corresponding to the LED17 occurs, the diagnostic voltage Vd in the diagnostic period Ta is approximately the same as the diagnostic voltage Vd in the other periods, as indicated by the broken line in fig. 4. Therefore, in step S205, it is determined whether the second detection value Vd2 is lower than the first detection value Vd 1. Here, if the second detection value Vd2 is not lower than the first detection value Vd1, that is, if the second detection value Vd2 is a value that is approximately the same as the first detection value Vd1, no in step S205, and the process proceeds to step S206.

In step S206, a failure site is specified. In this case, the second detection value Vd is approximately the same as the first detection value Vd1, and therefore it can be determined that an open fault corresponding to the LED17 has occurred. After step S206 is executed, the process proceeds to step S207. In step S207, the same failure occurrence processing as in step S105 in the first diagnostic method described above is executed. After step S207 is executed, the present process ends.

On the other hand, if the second detection value Vd2 is lower than the first detection value Vd1, yes in step S205, and the process proceeds to step S208. In step S208, energization to the other LED16 of the two LEDs 16, 17 that are not energized is performed. The period during which the LED16 is energized in step S208 is the diagnosis period Ta described above. In step S209, the diagnostic voltage Vd in the diagnostic period Ta during which the LED16 is energized is detected, and the detected value is acquired as the third detected value Vd 3.

When the open failure corresponding to the LED16 does not occur, the diagnostic voltage Vd in the diagnostic period Ta is lower than the diagnostic voltage Vd in the other periods, as shown by the solid line in fig. 4. On the other hand, when an open failure corresponding to the LED16 occurs, the diagnostic voltage Vd in the diagnostic period Ta is approximately the same as the diagnostic voltage Vd in the other periods, as indicated by the broken line in fig. 4. Therefore, in step S210, it is determined whether the third detection value Vd3 is lower than the first detection value Vd 1. Here, if the third detection value Vd3 is not lower than the first detection value Vd1, that is, if the third detection value Vd3 is a value that is approximately the same as the first detection value Vd1, no in step S210, and the process proceeds to step S206.

In this case, the third detection value Vd is a value that is about the same as the first detection value Vd1, and therefore, in step S206, it can be determined that an open fault corresponding to the LED16 has occurred. On the other hand, if the third detection value Vd3 is lower than the first detection value Vd1, yes in step S210, and the process ends. In this case, as a result of the failure diagnosis by the failure diagnosis device 20, a result that no failure has occurred in the light emitting unit 14 can be obtained.

【3】 Third diagnostic method

The third diagnostic method is a method capable of diagnosing a failure of the light emitting unit 14 when the operating state of the robot 2 is the second state, the fourth state, or the fifth state. The third diagnostic method is a method of diagnosing a failure of the light emitting unit 14, after slightly changing the control of the energization of the LEDs 15 to 17 of the light emitting unit 14 as compared with the normal state.

Specifically, in this case, the energization control unit 23 energizes the other plural (two) LEDs for a predetermined diagnosis period while the state of the robot 2 is a state in which only one LED of the light emitting unit 14 is energized. This diagnosis period is relatively short as the diagnosis period Ta in the second diagnosis method. In this case, as in the second diagnostic method, the energization control unit 23 controls energization of the other LEDs so that the brightness of the LED is lower than that in the steady state. In this case, the failure detection unit 25 detects a failure of the light emission unit 14 based on the detection value of the diagnostic voltage Vd during the diagnostic period.

In this case, the failure diagnosis apparatus 20(CPU21A) repeatedly executes the processing shown in fig. 6 at predetermined intervals. First, in step S301, it is determined whether or not the LED15 to the LED17 are in a state of being energized (the second state, the fourth state, or the fifth state). Here, when two or more LEDs among the LEDs 15 to 17 are in a state of being energized (first state or third state), no in step S301, and the present process ends. That is, in the third diagnostic method, when the robot 2 is in the first state or the third state, the failure diagnosis of the light emitting unit 14 is not performed.

On the other hand, if the current is supplied to only one of the LEDs 15 to 17 (the second state, the fourth state, or the fifth state), yes is performed in step S301, and the process proceeds to step S302. In the following description, each process will be described by taking as an example a case where only the LED15 is energized (second state), but the same process is also performed in a state where only the LED16 or the LED17 is energized (fourth state or fifth state).

In step S302, the diagnostic voltage Vd is detected, and the detected value is acquired as the first detected value Vd 1. Next, in step S303, energization to the two LEDs 16, 17 that are not energized is performed. The period during which the LEDs 16, 17 are energized in step S303 is the diagnosis period described above. In step S304, the diagnostic voltage Vd during the diagnostic period in which the LEDs 16, 17 are energized is detected, and the detected value is acquired as the second detected value Vd 2.

When the open failure corresponding to both the LEDs 16, 17 does not occur, the diagnostic voltage Vd in the diagnostic period is a voltage lower than the diagnostic voltage Vd in the other period by the amount of two LEDs energized. On the other hand, when an open failure occurs in one of the LEDs 16, 17, the diagnostic voltage Vd in the diagnostic period is lower than the diagnostic voltage Vd in the other period by the amount of LED energization. When an open failure occurs in both of the LEDs 16 and 17, the diagnostic voltage Vd in the diagnostic period is approximately the same as the diagnostic voltage Vd in the other period.

Based on this, in step S305, it is determined whether or not a value obtained by subtracting the second detection value Vd2 from the first detection value Vd1 is equal to or greater than the threshold value Vt 2. The threshold Vt2 corresponds to the amount of decrease in the diagnostic voltage Vd caused by the two LEDs being energized. Here, if the value obtained by subtracting the second detection value Vd2 from the first detection value Vd1 is equal to or greater than the threshold value Vt2, yes is performed in step S305, and the present process ends. In this case, as a result of the failure diagnosis by the failure diagnosis device 20, a result that no failure has occurred in the light emitting unit 14 can be obtained.

On the other hand, if the value obtained by subtracting the second detection value Vd2 from the first detection value Vd1 is smaller than the threshold value Vt2, no is performed in step S305, and the process proceeds to step S306. In step S306, it is determined whether or not a value obtained by subtracting the second detection value Vd2 from the first detection value Vd1 is equal to or greater than the threshold value Vt 1. The threshold Vt1 corresponds to the amount of decrease in the diagnostic voltage Vd caused by one LED being energized. Here, if the value obtained by subtracting the second detection value Vd2 from the first detection value Vd1 is smaller than the threshold value Vt1, no in step S306, and the process proceeds to step S307.

In step S307, a failure site is specified. In this case, it can be considered that the second detection value Vd2 is a value that is approximately the same as the first detection value Vd1, and therefore it can be determined that an open fault has occurred in correspondence with both LEDs 16, 17. After step S307 is executed, the process proceeds to step S308. On the other hand, if the value obtained by subtracting the second detection value Vd2 from the first detection value Vd1 is equal to or greater than the threshold value Vt1, yes is performed in step S306, and the process proceeds to step S309.

In this case, although it can be determined that an open fault corresponding to one of the LEDs 16, 17 has occurred, it cannot be determined which of the LEDs 16, 17 has occurred. Therefore, in step S309, a faulty portion determination process for determining a faulty portion is performed. The specific contents of the faulty portion determination processing are shown in fig. 7, for example.

First, in step S401, energization to one of the other LEDs 16, 17, for example, the LED16 is performed. The period during which the LED16 is energized in step S401 is the diagnosis period described above. Next, in step S402, the diagnostic voltage Vd during the diagnostic period in which the LED16 is energized is detected, and the detected value is acquired as the third detected value Vd 3.

When the open fault occurs corresponding to the LED17, the open fault corresponding to the LED16 does not occur, and therefore the diagnostic voltage Vd in the diagnostic period is lower than the diagnostic voltage Vd in the other periods. On the other hand, when the open failure occurs corresponding to the LED16, the diagnostic voltage Vd in the diagnostic period is approximately the same as the diagnostic voltage Vd in the other periods.

Therefore, in step S403, it is determined whether the third detection value Vd3 is lower than the first detection value Vd 1. Here, if the third detection value Vd3 is lower than the first detection value Vd1, yes in step S403, and the process proceeds to step S404. In step S404, it is determined that an open fault corresponding to the other LED17, which is the other LED16, 17, has occurred.

On the other hand, if the third detection value Vd3 is not lower than the first detection value Vd1, that is, if the third detection value Vd3 is a value that is approximately the same as the first detection value Vd1, no is issued at step S403, and the process proceeds to step S405. In step S405, it is determined that an open fault corresponding to one of the other LEDs 16, 17, i.e., the LED16, has occurred. After step S404 or S405 is executed, the faulty portion determination process ends, and the process proceeds to step S308. In step S308, the same failure occurrence processing as in step S105 and the like in the first diagnostic method described above is executed. After step S308 is executed, the present process ends.

As described above, according to the present embodiment, the following effects can be obtained.

The robot system 1 of the present embodiment includes a failure diagnosis device 20 for diagnosing a failure of the light emitting unit 14. The failure diagnosis device 20 includes: an energization control unit (23) which controls energization of the LEDs (15-17); a voltage detection unit (24) which detects a diagnostic voltage (Vd) that changes in accordance with the terminal voltages of the LEDs (15-17); and a failure detection section 25. The failure detection unit 25 detects a failure of the light emitting unit 14 based on the control status of the energization by the energization control unit 23 and the detection value of the diagnostic voltage Vd by the voltage detection unit 24.

Specifically, the failure detection unit 25 diagnoses a failure of the light emitting unit 14 based on whether or not an expected value of the diagnostic voltage Vd corresponding to the state of energization to the LEDs 15 to 17, which can be estimated from the control state of energization at that time, matches the detected value of the diagnostic voltage Vd. With this configuration, a failure of the light emitting unit 14 can be detected with high accuracy. The failure detection unit 25 also specifies the failure location in consideration of the difference in forward voltages of the LEDs 15-17 having different emission colors. Thus, it is possible to determine which of the LEDs 15-17 and the configuration for driving the LEDs 15-17 has failed.

In the robot system 1 having the above configuration, the following method can be adopted: that is, in a state where all of the LEDs 15 to 17 are not energized (not lit), any LED is energized (lit) to diagnose a failure of the light emitting unit 14. However, in this method, the state in which the light emitting unit 14 does not emit light is suddenly changed to the state in which the light emitting unit 14 emits light of a color that is not related to the operating state of the robot 2. In this case, since the light emitting unit 14 is shifted from the non-light emitting state to the light emitting state, such a change is easily recognized by an operator (user). Therefore, the operator may notice that the light emitting unit 14 suddenly emits light at a timing other than the timing expected by the operator, and may feel uneasy.

In contrast, in the first diagnostic method of the present embodiment, the failure of the light emitting unit 14 is diagnosed without changing the control of the energization of the LEDs 15 to 17 of the light emitting unit 14 as compared with the normal state. According to this first diagnostic method, since the operation of the light emitting unit 14 is the same as that in the normal state, the diagnosis of the light emitting unit 14 can be performed without giving the operator a sense of unease.

In the second diagnostic method according to the present embodiment, the energization control unit 23 energizes only one LED of the light emitting unit 14 for a predetermined diagnostic period Ta while the operating state of the robot 2 is in a state in which only the other LED is energized. In the third diagnostic method according to the present embodiment, the energization control unit 23 energizes the other two LEDs for a predetermined diagnostic period Ta while the state of the robot 2 is a state in which only one LED of the light emitting unit 14 is energized. In the second and third diagnostic methods, the failure detection unit 25 detects a failure of the light emission unit 14 based on the detection value of the diagnostic voltage Vd in the diagnostic period Ta.

According to the second and third diagnostic methods, the light emitting unit 14 does not suddenly change from a non-light emitting state to a light emitting state. In this case, the light emission color of the light emitting unit 14 changes only from the light emission color of the LED to which power is originally supplied to a mixed color in which the light emission colors of the other LEDs are mixed with the light emission color, and this change is difficult to be recognized by the operator. Therefore, according to the second and third diagnostic methods, the diagnosis of the light emitting unit 14 can be performed without giving the operator a sense of unease.

There are advantages in the first to third diagnostic methods, respectively. First, the first diagnostic method has an advantage that since it is not necessary to change the control of the energization of the LEDs 15 to 17 as compared with the normal time, the diagnosis of the light emitting unit 14 can be performed without changing the light emitting state of the light emitting unit 14 at all from the normal time. However, in the first diagnostic method, when the difference in forward voltages of the three LEDs 15 to 17 is small, it may be difficult to specify a failure site.

In contrast, in the second and third diagnostic methods, the LED different from the LED to which the current is originally supplied is supplied, and whether or not a failure associated with another LED has occurred can be detected based on whether or not the diagnostic voltage Vd in the diagnostic period Ta during which the current is supplied is lower than the diagnostic voltage Vd in another period. Therefore, according to the second and third diagnostic methods, there are the following advantages: that is, even when the difference in forward voltages of the three LEDs 15 to 17 is small, the failure point can be specified.

In the second and third diagnostic methods, the energization control unit 23 controls energization of the other LEDs so that the brightness of the LED is lower than that in a steady state. In this way, the degree of color change from the light emission color of the LED to the mixed color can be suppressed to a small level, and such a change is more difficult for the operator to recognize. Therefore, according to the second and third diagnostic methods, the diagnosis of the light emitting unit 14 can be performed while the possibility that the worker feels uncomfortable is further suppressed to a low level.

The second diagnostic method and the third diagnostic method are independently established, but they may be combined. For example, the diagnostic methods can be combined as follows: that is, first, the failure detection of the light emitting unit 14 by the third diagnostic method is performed, and when a diagnostic result that there is a possibility that a failure has occurred in the light emitting unit 14 is obtained, the failure detection of the light emitting unit 14 by the second diagnostic method is performed. Alternatively, the diagnostic methods may be combined as follows: that is, first, the failure detection of the light emitting unit 14 by the second diagnostic method is performed, and when a diagnostic result that there is a possibility that a failure has occurred in the light emitting unit 14 is obtained, the failure detection of the light emitting unit 14 by the third diagnostic method is performed. In this way, the following failure can be detected: although no problem occurs when the LEDs 15-18 are lit one by one, a failure occurs when a plurality of LEDs are lit, which is not lit due to an overcurrent or the like.

In the failure diagnosis device 20 of the present embodiment, the energization control unit 23 is configured to be able to control so as to ensure safety necessary for a user using the robot 2 even when the LEDs 15 to 18 are energized regardless of the operating state of the robot 2. With this configuration, even when the energization control unit 23 energizes the LEDs 15 to 18 in a manner different from the normal one for failure diagnosis of the light emitting unit 14, it is possible to eliminate the risk of lowering of the safety of the user.

In the failure diagnosis device 20 of the present embodiment, when the energization control unit 23 energizes the LEDs 15 to 18 regardless of the operating state of the robot 2, the respective light emission colors of the LEDs 15 to 18 are also colors that make it difficult for a user using the robot 2 to erroneously recognize the operating state of the robot 2. Thus, even when the energization control unit 23 energizes the LEDs 15 to 18 in a manner different from the usual manner for the failure diagnosis of the light emitting unit 14, the user does not erroneously recognize the operating state of the robot 2 due to the light emitting color of the light emitting unit 14, and therefore, the user does not come close to the robot 2 carelessly, and the risk of the safety degradation can be eliminated.

More specifically, the failure diagnosis device 20 of the present embodiment is a light emitting unit 14 including three LEDs, i.e., the R-LED15, the G-LED16, and the B-LED17, corresponding to the three primary colors of light. By energizing the LEDs 15-17 as described above, the light emitting unit 14 emits light of a color corresponding to the operating state of the robot 2. By using such a light emitting unit 14 as a target of failure diagnosis, the following effects can be obtained.

That is, in this case, the operating states of the robot 2 in which only one LED is energized are the second state, the fourth state, and the fifth state. According to the above configuration, even if the other LED is energized for the purpose of diagnosing a failure, that is, even if the diagnosis of the light emitting unit 14 by the second diagnosis method is performed, it is possible to eliminate the fear of the safety of the worker being lowered. The reason for this will be explained below.

First, when the robot 2 is in the second state, even if the B-LED17 is energized, the light emission color of the light emitting section 14 changes to magenta, which is a mixture of red and blue, and does not change to a color indicating another state of the robot 2, so that the worker does not erroneously recognize the operating state of the robot 2 and inadvertently approaches the robot, and the risk of a reduction in safety can be eliminated. When the robot 2 is in the second state, even if the G-LED16 is energized, the light emission color of the light emitting unit 14 changes to yellow, which is a mixture of red and green. In this case, yellow corresponds to the third state, and is a color indicating that the operation state of the robot 2 is wrong, as with red, which is the original light emission color. Therefore, even if the worker notices that the light emission color changes from red to yellow, the worker does not recognize that the operation state of the robot 2 is wrong, and does not approach the robot 2 carelessly, and the risk of the safety degradation can be eliminated.

When the robot 2 is in the fourth state, even if the R-LED15 is energized, the light emission color of the light emitting unit 14 changes to yellow, which is a mixed color of green and red. As described above, yellow is a color indicating that the operating state of the robot 2 is wrong. Therefore, even if the worker notices that the light emission color changes from green to yellow, the worker recognizes that the operating state of the robot 2 has changed from initialization to an error, and does not come close to the robot 2 inadvertently, so that the risk of a reduction in safety can be eliminated. Further, even when the robot 2 is in the fourth state, even if the B-LED17 is energized, the light emission color of the light emitting section 14 becomes cyan which is a mixed color of green and blue, and does not become a color indicating another state of the robot 2, so that the worker does not erroneously recognize the state of the robot 2 and inadvertently approaches the robot, and the risk of a reduction in safety can be eliminated.

When the robot 2 is in the fifth state, even if the R-LED15 is energized, the light emission color of the light emitting unit 14 changes to magenta, which is a mixed color of blue and red, and does not change to a color indicating another state of the robot 2, so that the worker does not erroneously recognize the state of the robot 2 and inadvertently approaches the robot, and the risk of a reduction in safety can be eliminated. Further, even when the power is supplied to the G-LED16 when the robot 2 is in the fifth state, the light emission color of the light emitting section 14 becomes cyan which is a mixed color of blue and green, and does not become a color indicating another state of the robot 2, so that the worker does not erroneously recognize the operation state of the robot 2 and inadvertently approaches the robot, and the risk of a reduction in safety can be eliminated.

Further, according to the above configuration, even if the other two LEDs are energized for the purpose of diagnosing a failure, that is, even if the diagnosis of the light emitting unit 14 by the third diagnostic method is performed, in the state where only one LED is energized (the second state, the fourth state, and the fifth state), it is possible to eliminate the fear that the safety of the worker is lowered. Further, according to the above configuration, even if the other LED is energized for the purpose of diagnosing a failure in the state where two LEDs are energized (third state), it is possible to eliminate the fear of the safety of the worker being lowered. The reason for this will be explained below.

That is, in these cases, the light emitting color of the light emitting section 14 is white. In the present embodiment, white is a color indicating a first state in which the robot 2 automatically performs a predetermined operation. Therefore, even if the operator notices that the light emission color of the light emitting unit 14 changes from the original color to white, the operator recognizes that the operating state of the robot 2 changes from the state indicated by the original color to the first state, and as a result, the operator does not inadvertently approach the robot 2, and the risk of a reduction in safety can be eliminated.

Thus, according to the above configuration, the following can be reliably prevented from occurring: although the operator may get in a state (particularly, the first state) of safety when he/she gets close to the robot 2 by mistake, the operator may get close to the robot by mistake because he/she thinks that the operating state of the robot 2 is a state (particularly, the fifth state) of no problem even if he/she gets close to the robot 2 by mistake based on the light emission color of the light emitting unit 14.

According to the second diagnostic method of the present embodiment, the following effects can also be obtained. First, by performing diagnosis in the second state where only the R-LED15 is energized, the following effects can be obtained. That is, since the second state is a state in which an error with a relatively high degree of importance has occurred, the operator does not come close to the robot 2 carelessly. Therefore, even if the other LEDs are turned on for a short time in the second state and the light emission color is instantaneously changed, the possibility that the worker approaches the robot 2 is extremely low. Therefore, by performing the diagnosis in the second state, it is possible to perform the failure diagnosis of the light emitting unit 14 while maintaining good safety.

In addition, by performing the diagnosis in the fourth state where only the G-LED16 is energized, the following effects can be obtained. That is, since the robot 2 is in the state during initialization in the fourth state, it is possible to diagnose a failure of the light emitting unit 14 during such initialization. Therefore, by performing the diagnosis in the fourth state, it is possible to prevent the robot 2 from shifting to the normal operating state in a state where the light emitting unit 14 has failed, and as a result, safety is improved.

Further, by performing the diagnosis in the fifth state where only the B-LED17 is energized, the following effects can be obtained. That is, the fifth state is a state in which the robot 2 is in the direct teaching mode. In general, direct teaching requires a relatively long time. Therefore, by performing the diagnosis in the fifth state, a relatively long time can be secured as a time for performing the failure diagnosis of the light emitting section 14, and the failure of the light emitting section 14 can be detected as soon as possible, resulting in improved safety.

In the second diagnostic method, an interval between a diagnostic period in which the current is supplied to the LED17 of one of the two LEDs 16, 17 that are not supplied and a diagnostic period in which the current is supplied to the LED16 is set according to the following idea, in other words, an interval between the time when the current is supplied to the LED17 and the time when the current is supplied to the LED16 is set. That is, when the interval is set so that the energization of the LED16 is performed after a relatively short time has elapsed after the energization of the LED17 is performed, the worker may be alerted to the change in the emission color based on the change in the emission color for the first time due to the energization of the LED17, and may be aware of the change in the emission color for the second time due to the energization of the LED 16.

Therefore, the above-described interval may also be set as follows: that is, after the energization to the LED17 is performed, energization to the LED16 is performed immediately. Since the emission color of the light emitting unit 14 changes continuously in this way, it is difficult for the operator to clearly recognize the changed emission color, and the possibility of keeping track of whether the original emission color has changed is low. Alternatively, the interval may be set as follows: that is, after the energization of the LED17 is performed, the energization of the LED16 is performed after a relatively long time has elapsed.

In this way, after the emission color is changed by the energization of the LED17, the emission color is changed again by the energization of the LED16 after a relatively long time has elapsed. Therefore, even if the worker notices the change of the emission color for the first time to a certain extent, the worker is less alert to the change for a relatively long time thereafter, and does not respond to the change of the emission color excessively, and the possibility of clearly noticing the change of the emission color for the second time is reduced.

The failure diagnosis device 20 includes a notification unit 26, and when a result of failure occurrence in the light emitting unit 14 is obtained as a result of failure diagnosis, the notification unit 26 performs a notification process of notifying an operator (user) of failure occurrence in the light emitting unit 14 by a method different from lighting of the LEDs 15 to 18. When a failure of the light emitting unit 14 is detected, the LEDs 16 to 18 may not be normally lit, and therefore, in the method of notifying the failure of the light emitting unit 14 by lighting the LEDs 15 to 18, there is a possibility that reliable notification cannot be realized. According to the above configuration, the occurrence of a failure in the light emitting unit 14 is notified by a method different from the lighting of the LEDs 15 to 18, and therefore, reliable notification can be realized.

In the present embodiment, as a specific method of the above notification, the following method can be adopted: that is, the power supply to the robot 2 is cut off to bring the robot 2 to an emergency stop. In this way, even if the operator erroneously recognizes the light emission color of the light emitting unit 14 due to the occurrence of a failure in the light emitting unit 14, the operation of the robot 2 is forcibly stopped, and therefore, it is possible to eliminate the risk that the safety of the operator is lowered due to the erroneous recognition.

In the configuration of the present embodiment, the resistor 22 for generating the diagnostic voltage Vd that varies according to the terminal voltage of the LEDs 15 to 17 is provided in the controller 3, and the voltage detection unit 24 detects the voltage at the terminal of the resistor 22 as the diagnostic voltage Vd. It is also possible to modify such a resistor 22 to be provided on the robot 2 side, instead of the controller 3 side. However, according to the structure of the present embodiment, there are the following advantages as compared with the structure of this modified example.

In the deformed row configuration, the number of cables 18 (the number of wires) connecting between the controller 3 and the robot 2 increases. That is, in the configuration of the present embodiment, only the wiring (power supply line L1) for supplying the power supply voltage Va to the light emitting unit 14 may be used, but in the configuration of the modified example, in addition to this, a wiring for introducing the diagnostic voltage Vd from the robot 2 to the controller 3 is necessary. That is, according to the configuration of the present embodiment, the number of wirings of one wiring 18 can be reduced as compared with the configuration of the modified example.

In the modified configuration, since the voltage detection unit 24 provided in the controller 3 detects the terminal voltage of the resistor 22 provided in the robot 2 through the wiring of the cable 18, there is a possibility that the detection accuracy of the diagnostic voltage Vd is lowered due to the influence of noise in the wiring, the influence of voltage drop in the wiring, and the like. In contrast, in the configuration of the present embodiment, since the voltage detection unit 24 provided in the controller 3 detects the terminal voltage of the resistor 22 similarly provided in the controller 3 as the diagnostic voltage Vd, the accuracy of detecting the diagnostic voltage Vd is not lowered by the influence of noise in the wiring, the influence of voltage drop in the wiring, or the like, and the accuracy of detecting the diagnostic voltage Vd can be improved as compared with the configuration of the modification.

(second embodiment)

A second embodiment in which the structure of the light emitting section is changed from that of the first embodiment will be described below with reference to fig. 8.

As shown in fig. 8, the light-emitting unit 31 of the present embodiment differs from the light-emitting unit 14 of the first embodiment in that it includes four R-LEDs 15, G-LEDs 16, B-LEDs 17, and the like.

In this case, the other terminal of the switch SWr is connected to the ground line L2 via the resistor Rr, and each of the four R-LEDs 15. In addition, in this case, the other terminal of the switch SWg is connected to the ground line L2 via the resistor Rg, and each of the four G-LEDs 16. In addition, in this case, the other terminal of the switch SWb is connected to the ground line L2 via the resistor Rb and each of the four B-LEDs 17.

According to the above configuration, the energization of the four R-LEDs 15 is controlled by the command signal Sr, the energization of the four G-LEDs 16 is controlled by the command signal Sg, and the energization of the four B-LEDs 17 is controlled by the command signal Sb. Therefore, in the above configuration, by the switch SWr being turned on, the four R-LEDs 15 are energized and lit; by the switch SWg being turned on, the four G-LEDs 16 are energized and lit; with switch SWb turned on, the four B-LEDs 17 are energized and lit.

The light emitting unit 31 having the configuration of the present embodiment described above can also be subjected to failure diagnosis by the failure diagnosis device 20 described in the first embodiment using the same method. In this case, it is not possible to determine which of the four R-LEDs 15 has failed as a determination of the failure location. In other words, in this case, it can be determined that a failure has occurred in one of the four R-LEDs 15. The same applies to the G-LED16 and the B-LED 17.

(other embodiments)

The present invention is not limited to the embodiments described above and shown in the drawings, and can be modified, combined, or expanded as desired without departing from the scope of the invention.

The numerical values and the like shown in the above embodiments are examples, and are not limited thereto.

The robot failure diagnosis device of the present invention is not limited to the robot system 1 which is a general industrial robot system, and can be applied to all robot systems including a light emitting unit which individually energizes and illuminates a plurality of types of LEDs having different light emission colors to emit light of colors corresponding to the state of the robot.

In the above embodiments, the resistor 22 for generating the diagnostic voltage Vd is provided upstream of the current-carrying path to the LEDs 15 to 17 (on the power supply line L3 side), and the voltage detector 24 detects the terminal voltage on the downstream side of the resistor 22 as the diagnostic voltage Vd. However, the resistor 22 can be provided downstream of the current supply paths to the LEDs 15 to 17 (on the side of the ground line L2). In this case, the voltage detection unit 24 detects the terminal voltage on the upstream side of the resistor 22 provided on the downstream side as the diagnostic voltage Vd.